Purification of liquids by distillation



Sept. 21, 1943. F. 1.. HUNTER PURIFICATION OF LIQUIDS BY DISTILLATION Filed July 31, 1940 INVENTOR PEFLUX CONAf/VSE)? FRA C T/ONATING HEATER SECTION COME]? AND cowmsms szcmw Patented Sept. 21, 1943 PURIFICATION OF nromos BY DISTILLATION Frederick L. Hunter, Lake Bluff, Ill., assignor to Fanstee] Metallurgical Corporation, North Chlcago, 111., a corporation of New York Application July 31, 1940, Serial No. 348,997

ficlaims.

This invention relates to apparatus for puriflcation of liquids by distillatiomand particularly to that type of apparatus which is suitable for removing dissolved gases from highly corrosive liquids.

It is an object of my invention to provide a single, unitary piece of apparatus which will efficiently remove dissolved gases from highly corrosive liquids, which apparatus is at the same time relatively cheap, simple of construction and easy to maintain in operating condition.

The foregoing object and other objects ancillary thereto are to be accompanied by the use oi apparatus illustrated in the accompanying drawing, in which the single figure is a conventionalized sectional elevation of the preferred embodiment of my invention.

In the drawing the four major elements of the apparatus, reading from top to bottom, are a reflux condenser designated generally at C, fractionating section designated F, a heater section designated H, a cooler and condenser section designated K.

The elements of the apparatus will be further described in connection with a description of the mode of operation of the apparatus as it is employed to purify liquid bromine contaminated with a small amount of dissolved chlorine. Raw liquid bromine is supplied at ill to the fractionating unit which for the purification of brothe operation of the device continues, the amount of heat supplied is controlled in order to permit an amount of bromine corresponding to the amount supplied at Ill, to'trickle down the wall M of the heater into the cooler and condenser K. Here the bromine is cooled on wall 28 to a temperature sufliciently low so that it is discharged at 30. It will be sufliciently cooled to be conducted to suitable storage, or other disposition. Cooling of the wall 28 is accomplished by the flow of cooling water supplied at 32 and withdrawn at 36. The walls oi both condensers mine is preferably constructed of heat-resistant glass and provided with packing consisting of /2" x A" Raschig rings, indicated at I 2. The liquid bromine flows down the packing and comes in contact with the heated wall I4 of the heater H. Excellent heat transfer is obtained if this wall be constructed of thin tantalum sheet, approximately .025" thick. The necessary heat is supplied by means of low pressure steam admitted through inlet iii of the jacket of the heater. The condensate is withdrawn from the outlet l8. As the liquid bromine'comes in contact with the surface M of the heater it boils and rises through the packing material. In this manner the whole body of bromine trickling down the packing l2 becomes heated to and above its boiling point, and the mixture of bromine vapor and the lighter chlorine gas are driven up into the reflux condenser section. The bromine condenses on the wall 20 and refiuxes down on the packing. The amount and temperature of the cooling water supplied at 22 and withdrawn at are preferably also constructed of tantalum sheet.

By employing a iractionating section 3" ameter by 36" long, filled with rings, a heater section 36" 2" in diameter to it" in diameter, a reflux condenser 30 "-long, tapering from 2" in diameter at the base to 1'. in diameter at the top, and a cooling condenser 24" long by in diameter, I have been able to purify upwards of 200 pounds in di- /2" glass Raschig long, tapering from per hour of bromine containing approximately 1.65 per cent chlorine. The finished product contained less than .05 per cent chlorine. Even with chlorine content as high as 6 per cent, the capacity of such a unit is of the order of 125 pounds per hour. By tapering the reflux condenser and the heater, I find that it is possible to restrain the velocity of liquid and vapor through these sections of the apparatus without at the same time causing the accumulation of any quiescent pools. Such apparatus, when constructed so that each unit is in vertical alignment with the other units, has the advantage that it is susceptible of assembly with only the simplest form of packing members between the units. The shape of the units is such that construction details are extremely simple, leaving no opportunity for the liquid or gas handled to accumulate at any point. In the case of apparatus constructed for the handling of such corrosive materials as chlorine and bromine, the advantage to be gained is tremendous.

Having thus described my invention in connection with the description, which is intended as exemplary only and not by way of limitation, what I claim as my invention is: r

1. Apparatus for fractionating by distillation comprising, in substantially vertical alignment, an elongated liquid-vapor contact section provided with means for feeding liquid to be fracas-to permit the chlorine to escape at 26, while the bromine is returned to the fractionator. As

tionated, and also provided with means for promoting gas and liquid contact, an-elongated condenser arranged vertically above said contact section, an elongated heater arranged vertically below said contact section, and an elongated cooler arranged vertically below said heater section, said condenser, heater and cooler sections being free of pool-forming obstructions and being provided with interior peripheral walls, said walls being so inclined to the horizontal that no substantial amount of liquid can come to rest thereupon.

2. Apparatus according to claim 1, wherein the condenser is tapered, having a lesser cross-section at the top than at the bottom.

3. Apparatus according to claim 1, wherein the heater is tapered, having a lesser cross-section at the bottom than at the top.

4. Apparatus according to claim 1, wherein the condenser is tapered, having a lesser cross-section at the top than at the bottom, and wherein a water jacket is provided for the condenser having greater cross-sectional area at the top than at the bottom.

5. Apparatus according to claim 1, wherein the heater is tapered, having a lesser cross-section at the bottom than at the top, and wherein a steam jacket is provided as 'a part of the heater, having greater cross-sectional area at the bottom than at the top.

6. Apparatus for fractionating by distillation comprising, in substantially vertical alignment, an elongated liquid-vapor contact section provided with means for feeding liquid to be fractionated, intermediate the length thereof, and also provided with means for promoting gas and liquid contact, an elongated condenser arranged vertically above said contact section, an elongated heater arranged vertically below said contact section, and an elongated cooler arranged vertically below said heater section, said condenser, heater and cooler sections being free of poolforming obstructions and being provided with interior peripheral walls, said walls being so in clined to the horizontal that no substantial amount of liquid can come to rest thereupon.

FREDERICK L. HUNTER. 

